1. Field of the Invention
This invention relates to toothpaste compositions, and, more particularly, to a toothpaste dentifrice with strontium capable of desensitizing the nerve endings of a tooth in saliva or water because of an extension of the contact time of the strontium ions on the tooth surface.
2. Description of the Prior Art
Rosenthal, in U.S. Pat. No. 3,122,483, issued Feb. 25, 1964, described a water-containing toothpaste for tee treatment of hyper-sensitive dentin characterized by including therein water-soluble strontium compounds that release strontium ions from solution. The strontium compounds disclosed were the strontium chloride, acetate, bromise, lactate, iodide, nitrate and salicylate.
However, this and other patents, publications and commercial products for treating hyper-sensitive dentin have inherent disadvantages: (1) the strontium compound may not provide an adequate concentration of strontium ions in aqueous solution, i.e. the strontium compound may not be very soluble in water; (2) even if present in water, the strontium ions may not adhere particularly well to the tooth surface where it can perform its desensitizing action; (3) accordingly, the contact time of strontium on the tooth may be quite short, and thereby its effectiveness diminished; (4) the strontium ions are susceptible to being precipitated out of solution by the presence of other components in the composition; and (5) inorganic strontium compounds do not provide a film on the tooth surface.
Accordingly, the object of the present invention is to provide an improved toothpaste composition which overcomes the deficiencies of the prior art and commercial products for treating pain caused by sensitive teeth.